Modulating control



Aug. 25, sHl'VE S 2,052,536

I MODULATING CONTROL Original Filed Nov. 1, 1950 4 Sheefs-Sheet 1 INVENTOR N I Paul IFS/1176215,

A TTORNEYS Aug. 25, 1936. HN 2,052,536

MODULATING CONTROL Original Filed Nov. 1, 1930 4 Sheets-Sheet 2 INIVENTOR. Paul 1 5611/6127,

A TTORNEY5 Aug. 25, 1936. P. F. SHIVERS MODULATING CONTROL Original Filed Nov. 1, 1930 4 Sheets-Sheet 3 mmmmm IVC."

A TTORXEYS Aug. 25, 1936.

P. F. SHIVERS MODULATING CONTROL Original Filed Nov, 1, 1930 4 Sheets-$heet 4 IN VEN TOR.

Pa ul 1 J/YZI/ezzs', BY

way/764L150,

A TTORNEYS Patented Au 25, i936 MODULATING con'rnor.

Paul F. Shivers, Wabash, Ind., assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Application November 1, 1930, Serial No. 492,741 Renewed October 13, 1933 29 Claims. (Cl. 236-B8) The object of my present invention is to provide thermostatic mechanism wherein a power delivery element may be caused to assume and maintain a definite position desired by reason of the temperature at a given point. More specifically, the object of the invention contemplates the utilization of the power delivery element for positioning a flow-controlling element, which, in some instances will affect the action of the thermostatic mechanisms in accordance with temperatures acquired as a resultof controlled flow.

. The invention, as broadly stated above, may be embodied in various specific forms and therefore, more specifically, the object of my invention is to provide an apparatus:

(a) In which the rate of delivery of a heating medium to a compartment may be varied inversely as the temperature of the compartment falls below a desired minimum. I

(b) In which the rate of flow of a fluid through a valve structure may be varied in accordance with the variation, from a desired maximum or minimum, of the temperature at a predetermined point.

' (c) In which the rates of flow of a plurality of fluids may be concurrently varied proportionately as a result of the variation, from a desired maximum or minimum, of the temperature at a predetermined point;

The accompanying drawings illustrate, diagrammatically, embodimen of my. invention.

Fig. 1 is a diagram of a paratus capable of controlling the rate of flow of an electric current 35 to a heating element in accordance with the temperature needs of an isolated compartment;

Fig. 2 is a diagram of a valve mechanism capable of modulating the rate of flow of a fluid therethrough in accordance with the tempera- 40 ture conditions at a remote point;

Fig. ,3 is a diagram of apparatus capable of proportionately modulating the rate of flow of two liquids in accordance with the temperature conditions at a remote point; and

45 Fig. 4 is a diagram illustrating an application of my improved control device for modulating the carrying a contact terminal H and being most conveniently electrically conductive. Arranged to be contacted with terminal H is a terminal l2 carried by a bi-metallic thermostatic blade l3 which is most conveniently not as sensitively re- 5 sponsive to variations in desired temperature of chamber 6 as is blade Ill. The two blades Ill and I3 are arranged was to be temperature-responsive in opposite directions and associated with blade I3 is an electrical heating element I 4. 10

At a point remote from chamber 6 is a motor element l5 which, in the present instance, is illustrated as an expansible and contractible bellows capable of actuating the power-delivery element l6. Communicating with the interior of 15 bellows l5 through a pipe I! is the interior of a metal capsule l8 preferably packed with copper wool l9, said bellows, tube and capsule containing a volume of volatile liquid 20 sufllcient to flll the same when the bellows is collapsed to its 20 limit.

Carried by element IE, but electrically insulated therefrom is an electrical terminal 2| having a face 22 inclined slightly from the line of I movement of plunger [6, as shown in the draw- 25 ings.

A terminal 23, carried by a bimetallic thermostatic blade 24, is so arranged that terminal 23 is Just out of contact with terminal 2| when the bellows I5 is fully collapsed and so that heating of blade 24 willcarry terminal 23 into contact with'terminal 2|, whereupon heating of capsule l8 will cause terminal 2! to be elevated .to break the contact between terminal 23 and terminal 2|.

Associated with blade 24 is an electrical heating element 25, one end of which is connected by wire 26 with one end of coil l4 and the other end of which is connected by wire 21 with one end of the secondary of a transformer T, the primary of which is connected to the line wires 30 .and 3|.

The other end of the secondary of transformer T-is connected bywire 32 with blade l0, and consequently with terminal I I. One end of heating element I4 is connected to terminal l2 either directly or through blade I3. v

modulating type i. e., one in which currentyariation is by infinitesimal steps; Wire 3 is connected to one end of this rheostat and a wire 4| connects the other end of this rheostat to line wire 3 I ,.con-. veniently by connection with wire 36.

Rheostat R. may be of any desired effective type and I have illustrated diagrammaticallya type wherein the movable terminal 5|], to which wire 9 is connected, is an iron wedge, of varying crosssection, depending in a saline solution 5| submerging a copper terminal 52 to which wire 4| is connected.

For the purpose of varying the efiectiveness of rheostat R, the terminal 50 is suspended bye. cord 53 attached to a lever 54 actuated by plunger I6, said lever 54 carrying a suitable counter-weight 55 for purposes of calibration and adjustment.

A switch x may be provided in the line 30, 3|.

- Fig. 1 are similarly designated. This device is a The operation is as follows:

At temperatures below the desired temperature within chamber 6, blade l causes terminal II tocontact with terminal I2, and thus closes the cir- 40 Y terminal 50 is in position to permit minimum curcuit T, 32, I0, H, l2, l4, 26,25, 21, T, whereupon element I4 will be heated causingterminal |2 to move away from terminal II' and element 2 will be heated causing terminal 23 to move into contact with terminal 2|, whereupon the circuit 3|, 35, 35, 31, 2|, 23, 24, '40, 30 will be closed, the element 35 willbe heated, and the liquid 2|| will be volatilized to'an extent sufilcient to cause bellows I5 to expand until terminal 2| separates from terminal23.- Blade II] will have been. adjusted, conveniently by means of a common adjustable mounting for its anchored end, so that terminal II will just contact with terminal 2 when thetemperature of the interior of chamber 6 is at the desired maximum.

' The heating of elements I4and 25 willcontinue until terminal I2 is retracted from terminal I I. When the bellows is in its collapsed position rent flow to element 1. i

When the circuit of elements.35 and" 25 is broken byretraction of terminal I2 from terminal II, blade I3 will cool and move terminal l2 back toward terminal II. and blade 24. will cool so as to move terminal 23 away from terminal 2|.

Upon lapse of aeomparatively short time so long as blade I0' is at a temperature below the desired maximum of temperature in chamber 6, terminal I2 will again contact with terminal Ill and again elements I4 and 25 will be heated and the cycle already described will be repeated.

So long as blade I0 is in any position belowthe position which it will attain when at the desired maximum temperature, blade I3 will vibrate to intermittently'contact terminal I2 with terminal II and, bellows I5 being expanded, terminal 50 will permit a flow of current to element 1 proportionate to the degree of departure of the temperature in chamber 6 below the desired maximum.. 1

'The intermittent contacting between terminals,

II and I2 willoccur at comparatively short intervals, and the consequent intermittent heating of the element 25 will cause-the blade'24 to assume, and retain within a very limited range of'varias tiori, a position whichwill be a function of the contemporaneous position of the blade I0.

Each time terminal 23 contacts with terminal 2| the heating element '35 will be energized and each time terminal 23 separates from terminal 2| the, circuit of the heating element 35 will bebroken. There will consequently be volatilization of the liquid 20 atshort intervals and corresponding slight fluctuation of the position of element I6. The separation between terminals 23 and 2| will be a result of the coordinated movements of those terminals, one underthe influence of the heating element 25 and the other 'under the inthe relation of terminal 50 to the conductive solu- -tion 5| to determine the rate of flow of current to the heater element. I, in accordance with the heat needs of chamber 6 as indicated by the con temporaneous position of blade I0.

In the diagram Fig. 2, parts which correspond in structure and function with similar parts in modulating valve Eapable of controlling the rate of fiow of a fluid, the valve structure performing a function analogous to the function performed ,static blade I3 coordinated with the heater element I4. The element I6 of 'the'bellows I5 is the actuating stem of a valve V coacting'with the seat S of the valve casing VC, element I5 being coordinated with a suitable fluid-tight packing, as for instance the sealing diaphragm D. The bellowsactuated terminal 2| coacts with terminal 23 carried by bimetallic blade 24 which may be heated by element 25 one end of which isconnectedby wireBIl to line 30 and the otherend of which is 1 connected bywire 6| with terminal II through with line'30.

Bellows I5 communicates through pipe with capsule I8, which capsule is heated by coil 35,

one end of which is connected by wire 31 with terminal 2| and the other end of which is connected by wire 36 with line 3|. The .cooperation of the parts is substantially blade Ill. The blade 24 is connected by-wire 40 4'0 theisame as in the arrangement shown in Fig.

. 1. In this instance-the power-delivery element I6,is definitely positioned in accordance with the contemporaneous position assumedvby blade Ill,

and this serves to.position' valve V relative to the seat S to control the rate of flow through the valve casing VC in accordance with the contem poraneous temperature position of the blade III. In this connection it should be understood that. in this apparatus. the power-delivery ,ele-' 'ment is not rapidly shifted from maximum to minimum position when electrical contacts are broken at |||2 or 2I--23 but, instead, is modu- "lated from one position 'to another throughout its range in accordance with the contemporane- 'ous position which :the temperature-responsive blade I0 assumes, or tends to assume, due to the 65 temperature of the ambient medium.

As a consequence the accuracy of flow control is very much greater than can be .attained by a ,structure in which the'flowrcontrolling valve is intermittently closed to stop flow and 7 opened to permit maximum flow.

The arrangement shown in Fig; 3 is substan tially the same as that shown in Fig. 2,, except that an additional valve and valve casing is provided and the, valve elements areslightly modified inform.,

aouaase Here the element I3 carries two valve elements V' and V" which coact respectively with seats S and S of the valve casings VC' and V".

The valves V and V" are manipulated synchronously by the motor bellows I5 and they are so formed that their adjustments relative to their ing means beingcontrolied by the coaction of one of the two first-mentioned thermostatic means and the third element, and a power-delivery (plunger I6) capable of being actuated by means (bellows I5, capsule I8, heater 35) controlled by the coactionof an element carried by the other of said thermostatic means (terminal 23) and an element positioned by the actuating means (terminal 2 I In the species shown in Fig. 1 the element I6 controls means by which the flow of elec- 0 tric fluid to the heater 1 is determined which, in

turn, affects the positioning of the third thermostatic element, whereas in the species shown in Figs. 2 and 3, the element I6 determines the positioning of valves which modulate fluid flow.

In Fig. 4 the fundamental elements are substantially the same as those in the preceding strmtures and are designated by the same reference numerals. In this construction, however, the

wiring is slightly different. Line is connected by a wire 80 with one end of coil I4 and by a wire 8| with blade 26. The opposite end of coil I 4 is connected to terminal I2 through-blade l3. Wire 82 connects terminal II, through blade III, with one end of coil 25 and the other end is connected by wire 84 with line wire 3|.

One end of coil 35 is connected by wire 31 with terminal.- 2I and the other end of said coil is connected by wire 36 with line wire 3i through wire 84. The power delivery element I6 is connected with a lever 54' provided with an adjustable counterweight and this lever is connected, at its opposite ends, by cables 86 and 81 respectively. with the check damper 8'8 and the draft damper 89 of a warm air furnace 90.

55 As in the previously described constructions,

the coaction between terminals II and I2 will result in a modulated positioning of terminal 23 in accordance with the position to which terminal II is being urged by blade I0 under the influence of the temperature of its ambient medium, and the coaction between terminals 23 and 2| will result in the correspondingly modulated positioning of the power delivery element 54' which, in

turn, produces a correspondingly modulated positioning of the draft damper 89 and check damper At the present time the draft and check dampers ofwarm air furnaces are commonly controlled by a motor mechanism, either electric or spring, having two defined at-rest positions, which position the draft and check dampers at one or the other oftheir extremes of motion so that the '75 fully closed or wide open.

In the present construction the damper motive mechanism is such that the dampers may be maintained in desired intermediate positions or at their extremes, depending entirely upon the position to which terminal I I is being ultimately urged by reason of the current temperature of the ambient medium of the thermostat I0.

It will be readily understood that the element II), in many installations, need not be a thermostatic element but may be a circuit-controlling element responsive to local conditions and coacting with element I3 to control the heating of elements I3 and 24.

Terminal 2| is made of such length that its lower end will be shifted clear of terminal 23 before bellows I5 passes a safe limit of expansion so that capsule I8 can never be heated by coil 35 enough to cause rupture of the bellows.

I claim as my invention:

1. The combination of a thermostatic element, a heater by which said element may be locally heated, a second thermostatic element, a heater by which the second thermostatic element may be locally heated, a heat source for energizing said heaters, a third element responsive to local conditions coacting with the first-mentioned thermostatic element to intermittently connect the heat source with the heaters depending upon the responsive positions of the first and third elements, a power delivery element, means for shifting said power delivery element in opposite directions, and means comprising an element positioned-by the power delivery element and an element positioned by the second-mentioned thermostatic element for controlling the application of said shifting means to the power delivery element.

2. The combination of a thermostatic element,

an electric heater therefor, a second thermostatic element, an electric heater therefor, a source of energy for said. heaters, a third element responsive to local conditions, means carried respectively bythe first and third elements for controlling the connection between said heaters and the energy source therefor, a power delivery element, means for applying force thereto to cause the same to shift in either of two directions, and means comprising an element positioned by the power delivery element and an element positioned by the second thermostatic element for controlling the application of force to said power delivery element.

3. The combination of a thermostatic element, an electric heater therefor, a second thermostatic element, an electric heater therefor, a source of energy for said heaters, a third element responsive to local conditions, means carried respectively by the first and third elements for controlling the connection between said heaters and the energy source therefor, a power delivery element, an expansible and contractible element for actuating said power delivery element in either of two directions, temperature-responsive fluid afiecting said expansible and contractible element, an electric heater by which a portion of said flu d may be heated, and an energizing circuit for said lastmentioned heater, said energizing circuit comprising a terminal positioned by the expansible and contractible element and a cooperating terminal positioned by the second-mentioned thermostatic element.

' 4. Apparatus having the characteristics specified in claim 1 and comprising an electric heater arranged to efiect positioning of the said third element, an energizing circuit for said last-mentioned heater including a rheostat for controlenergizer to said heater, said'means comprising an element positioned by the power delivery elementvand a coacting element positioned by the second thermostatic element.

6. Apparatus having the characteristics specifled in claim 2 and comprising an electric heater arranged to efiect positioning of the said third. element, an energizing circuit for said last-mentioned heater including a rheostat for controlling the rate of power delivery thereto, and a connection between the movable element of said rheostat and the power delivery element.

7.. Apparatus having the characteristics specified in claim 2 and comprising a heater arranged to effect positioning of the "said third element,

an energizer for. said last-mentioned heater, and means for controlling the application-of said. energizer; to said heater, said means comprising an element positioned by the power delivery element and a coacting element positioned by the second thermostatic element.

8.-Apparatus having the. characteristics specified in claim 3 and comprising an electric heater T tionedheater including a rheostat for controlling means for :controlling the application of said arrangedto effect positioning of the said third element, an energizing circuit for said last-menthe rate of power delivery thereto, and a connection between the movable element .of said rheostat and the power delivery element; 9. Apparatus having the characteristics specifled in claim 3 and comprising a heater arranged to effect positioning of the said third element, an energizer for said last-mentioned heater, and

energizer tov said heater said means comprising an element positioned by the power delivery element and a coacting element positioned by the .second thermostatic element. g

10. Apparatus having the characteristics speci-- fled'in claim 1 and comprising'a flow-controlling Y valve, the movable element of-wliich is connected 50 to the power delivery element.

11. Apparatus having the characteristics speciiied in claim 2 and comprising a flow-controlling valve, the movable element of which is coniiected to the power delivery element.

12. Apparatus having the characteristics speci-- fled in claim 3 and comprising a flow-controlling valve, the movable element of which is connected to'the power delivery element.

13. Apparatus of the-[character specified in claim'l and comprising twovalves, the movable elements of which are connected to said power delivery element.

14. Apparatus of the character specified in claim 2 and comprisingtwo valves, the movable elements of which are connected to said power delivery element.

15. Apparatus of the character specified in claim 3 and comprising twovalves the. movable said power elements of which are connected to delivery element;

16; Apparatus having the characteristics specifled in claim 1 and comprising a fuel burning heater, means for controlling the combustion of fuel in said heater and connections.,.between' said control means and the power delivery element termined extent. i

' said circuit, said switch including a thermo-resecond terminal-associated with said bellows, a

thermo-responsive arm, a terminal carried by -for modulating the position of said control means between its limits.

17. Apparatus vhaving the characteristics speci- V fied in claim -2 and -.comprising a fuel burning heater, means forcontrolling the combustion or 6 fuel in said heater andconnections between said control means and the power delivery element for modulating the position of said control means between its limits. 5

18. Apparatus having the characteristics speci- 10' fled in claim 3 and comprising a fuel burning heater, means for controlling the combustion of fuel in said heater and connections between said control means and the power delivery element for modulating the position of said control means between its limits.

"19. Apparatus of the character specified in claim 1 and comprising a heating furnace having draft and check dampers, and connections between said draft and check dampers and the 20,

power delivery element for simultaneously modulating in'opposite directions the positions of said draft and check dampers between their limits of movement.

20. The combination of a thermostatic ole-"25.

ment, a heater by which said element may heated, a second thermostatic element, a heater by which said second thermostatic element may be locally heated, a heat source for energizing said heaters, a third element responsive to local conditions coacting with the first thermostatic element to intermittently connect the heat source with the heaters depending upon the responsive positions of 'theflrst and third elements, an expansible bellows, a thermally responsive medium in said bellows, ,an electric heater coordinated with said thermally responsive medium, and an energizing circuit for said heater comprising 00-, acting terminals carried respectively by the secondthermostatic element and the bellows and 40 so proportioned as to definitely-break the heater circuit when the bellows is expanded to a prede- .'21. .In combination, a bellows, a capsule coneIement associated with said capsule, a circuit for energizing said heating element, and a switch in sponsive arm, a terminalcarried by said arm, a

second electric circuit, a'heat'er in saidlast-mentioned circuit and arranged to afiect said am,

' said arm being movable, when heated, to 'estab- .lish said energizingcircuit, and said second terminal being movable, upon expansion oi-said bellows, to break said. energizing circuit, and means for controlling said second-mentioned circuit.

22. In con i ination, a bellows, 'a capsule containing heat-responsive fluid communicating I with the interior of said bellows, an electric heating element associated with said capsule, a cirtaining heat-responsive fluid communicating with at l the interior'of said bellows, an electric heating .ico

cuitfor energizing said heating element, and-a switch in said circuit, said switch including a said arm, a second terminal associated with said bellows, a second electric circuit, a heater in said last-mentioned circuit and arranged to afiect said arm, said arm being movable, whenheated,

to establish said energizing circuit, and said sec-- 4 j ond terminal being movable, upon expansion of said bellows, to break said energizing circuit, and

means for controlling said second-mentioned circuit,saidlast-mentioned means comprising a 7 second thermostatic arm and an element responsive to local conditions, terminals carried by said last-mentioned arm and by said element and connected in said last-mentioned circuit, and a third heater connected in said last-mentioned circuit and associated with said last-mentioned arm, said heater tending, when energized, to move said arm to break said last-mentioned circuit.

23. In combination, a bellows, a capsule containing heat-responsive fluid communicating with the interior of said bellows, an electric heating element associated with said capsule, a circuit for energizing said heating element, and a switch in 'said circuit, said switch including a movable .arm, a terminal carried by said arm, a second terminal associated with said bellows, a second electric circuit, an actuator connected in said second circuit and arranged, when energized, to move said arm to establish said energizing circuit, said second terminal being movable, upon expansion of said bellows, to break said energizing circuit, and means responsive to variations in physical conditions at a predetermined point for controlling said second circuit.

24. In combination, a bellows, a capsule containing heat-responsive fluid communicating with the interior of said bellows, an electric heating element associated with said capsule, a circuit for energizing said heating element, and a switch in said circuit, said switch including a movable arm, a terminal carried by said arm, a second terminal associated-with said bellows, a second electric circuit, an actuator connected in said second circuit and arranged, when energized, to move said arm to establish said energizing circult, said second terminal being movable, upon expansion of said bellowsgto break said energizing circuit, and means for controlling said second circuit, said last-mentioned means comprising an element movable in response to local conditions, a-terminal carried thereby, a movable member, a terminal carried thereby, said lastmentioned' terminals being cooperatively arranged and connected in said last-mentioned circuit, an electric actuator connected in said lastmentioned circuit, and operable, when energized, to shift said member to break said last-mentioned circuit.

25. The combination of an element, an actuator therefor, a second element, a second actuator for said second element, a power source for energizing said actuators, a member responsive to local conditions co-acting with said first element, to intermittently connect said power source with said actuators depending upon the responsive positions of said first element and said member, a motor, means for energizing said motor including an electric circuit comprising co-acting terminals carried respectively by said second element and a member shiftable by said motor, said terminals being so proportioned and arranged as to definitely break said circuit upon actuation of said motor in one directionv to a predetermined extent. 4,

26. The combination of an element, an actuator therefor, a second element, a second actuator for said second element, a power source for energizing said actuators, a member responsive to local conditions co-acting with said first element to intermittently connect the power source with the actuators depending upon the responsive positions of said first element and said member, a power delivery element, a reversible motor operatively connected thereto, and means comprising an element positioned by said power delivery element and an element positioned by the second element for controlling said motor.

27. The combination of, a thermally-responsive element, an electric terminal variably positioned thereby, a second thermally-responsive means, an electric terminal variably positioned thereby within cooperative range of the first-mentioned terminal, an electric heater for said first-mentioned themially-responsive element, an energiz- I ing circuit for said heater controlled by said two terminals, electric heating means for said second thermally-responsive means, and an energizing circuit for said last-mentioned heating means including an element responsive to its local conditions for variably affecting the heating effect of said last-mentioned heating means to variably position the second thermally-responsive means in accordance with variations in said local conditions.

28. A modulating system comprising, an electrically energized power delivery element, an electric terminal variably positioned thereby, a thermany-responsive means, an electric terminal variably positioned thereby within cooperative range of the first-mentioned terminal, an electric,

energizing circuit for said power delivery element including said two terminals, electric heating means for said thermally-responsive means, and

' arm, a terminal carried by said arm, a second terminal' associated with said bellows, a second electric circuit, an actuator connected in said second circuit and arranged, when energized, to move said arm to establish said energizing circuit, said second terminal being movable, upon expansion of said bellows, to break said energizing circuit, and means responsive to variations in physical conditions at a predetermined point for variably energizing said second circuit in accordance with variations in said physical condition.

PAUL F. SHIVERS. 

